(1) Field of the Invention
The present invention relates to a license management system in which a license management server centrally manages usage of a content on a terminal device. Particularly, it relates to a parental control system in which a parent sets a usage restriction on a child's usage of a content in the home and a temporary usage restriction system in which a restriction is set on usage of a content by a temporary user who uses the content using another's terminal device temporarily.
(2) Description of the Related Art
In recent years, since people of all ages have been able to view and enjoy contents such as TV and radio programs, videos, CDs (compact discs) and comic books easily on their personal computers or the like in their homes, children have had increasing opportunities to view adult or violent scenes in these pictures. So, in these homes, consideration is required to preventing the children from viewing these inappropriate scenes included in the pictures so that they do not have a bad influence on the children's mental development. It is a parental control system that gains the spotlight from this viewpoint.
In the conventional content distribution system, schemes to prevent the selling of an adult content to an underage user by checking the user's age in purchasing the content or regarding the user who offers to purchase the content by a credit card as an adult. Also, as for a DVD (digital versatile disc) video, parental control codes represented as numbers of 1˜8 are preset on a DVD disc for sale, and a parent presets the code indicating a rating level of the video that can be reproduced on a reproduction device in his home.
And, when the code value set on the reproduction device is smaller than that of the DVD disc, the DVD video cannot be reproduced on the reproduction device. For example, when the parental control code of the DVD disc is 3 and the code of the reproduction device is 2, the DVD video cannot be reproduced on the reproduction device. Since a 4-digit password is necessary to change the code of the reproduction device, a child cannot change the code by himself.
However, most of these conventional systems control the reproduction device only to reproduce or not to reproduce a content, and cannot put detailed restrictions such as the restriction on a usage duration or a usage number of the content. There is also a problem that although only a violent scene can be cut out of a DVD video, a parent cannot set restriction rules and details individually such as which scene should be cut out or how a rating level of a parental control code should be set. All he can do is put restrictions under the predetermined rules.